1# ===========================================================================
2#     http://www.nongnu.org/autoconf-archive/ax_check_compiler_flags.html
3# ===========================================================================
4#
5# SYNOPSIS
6#
7#   AX_CHECK_COMPILER_FLAGS(FLAGS, [ACTION-SUCCESS], [ACTION-FAILURE])
8#
9# DESCRIPTION
10#
11#   Check whether the given compiler FLAGS work with the current language's
12#   compiler, or whether they give an error. (Warnings, however, are
13#   ignored.)
14#
15#   ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
16#   success/failure.
17#
18# LICENSE
19#
20#   Copyright (c) 2009 Steven G. Johnson <stevenj@alum.mit.edu>
21#   Copyright (c) 2009 Matteo Frigo
22#
23#   This program is free software: you can redistribute it and/or modify it
24#   under the terms of the GNU General Public License as published by the
25#   Free Software Foundation, either version 3 of the License, or (at your
26#   option) any later version.
27#
28#   This program is distributed in the hope that it will be useful, but
29#   WITHOUT ANY WARRANTY; without even the implied warranty of
30#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
31#   Public License for more details.
32#
33#   You should have received a copy of the GNU General Public License along
34#   with this program. If not, see <http://www.gnu.org/licenses/>.
35#
36#   As a special exception, the respective Autoconf Macro's copyright owner
37#   gives unlimited permission to copy, distribute and modify the configure
38#   scripts that are the output of Autoconf when processing the Macro. You
39#   need not follow the terms of the GNU General Public License when using
40#   or distributing such scripts, even though portions of the text of the
41#   Macro appear in them. The GNU General Public License (GPL) does govern
42#   all other use of the material that constitutes the Autoconf Macro.
43#
44#   This special exception to the GPL applies to versions of the Autoconf
45#   Macro released by the Autoconf Archive. When you make and distribute a
46#   modified version of the Autoconf Macro, you may extend this special
47#   exception to the GPL to apply to your modified version as well.
48
49AC_DEFUN([AX_CHECK_COMPILER_FLAGS],
50[AC_PREREQ(2.59) dnl for _AC_LANG_PREFIX
51AC_MSG_CHECKING([whether _AC_LANG compiler accepts $1])
52dnl Some hackery here since AC_CACHE_VAL can't handle a non-literal varname:
53AS_LITERAL_IF([$1],
54  [AC_CACHE_VAL(AS_TR_SH(ax_cv_[]_AC_LANG_ABBREV[]_flags_[$1]), [
55      ax_save_FLAGS=$[]_AC_LANG_PREFIX[]FLAGS
56      _AC_LANG_PREFIX[]FLAGS="$1"
57      AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
58        AS_TR_SH(ax_cv_[]_AC_LANG_ABBREV[]_flags_[$1])=yes,
59        AS_TR_SH(ax_cv_[]_AC_LANG_ABBREV[]_flags_[$1])=no)
60      _AC_LANG_PREFIX[]FLAGS=$ax_save_FLAGS])],
61  [ax_save_FLAGS=$[]_AC_LANG_PREFIX[]FLAGS
62   _AC_LANG_PREFIX[]FLAGS="$1"
63   AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
64     eval AS_TR_SH(ax_cv_[]_AC_LANG_ABBREV[]_flags_[$1])=yes,
65     eval AS_TR_SH(ax_cv_[]_AC_LANG_ABBREV[]_flags_[$1])=no)
66   _AC_LANG_PREFIX[]FLAGS=$ax_save_FLAGS])
67eval ax_check_compiler_flags=$AS_TR_SH(ax_cv_[]_AC_LANG_ABBREV[]_flags_[$1])
68AC_MSG_RESULT($ax_check_compiler_flags)
69if test "x$ax_check_compiler_flags" = xyes; then
70	m4_default([$2], :)
71else
72	m4_default([$3], :)
73fi
74])dnl AX_CHECK_COMPILER_FLAGS
75